---
name: "VistaIOError"
section: "3"
platform: "linux"
package: "libvistaio-dev"
version: "1.2.19-3+b2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/VistaIOError"
---

# VistaIOError(3)

report a fatal error

## NAME

VistaIOError, VistaIOSystemError - report a fatal error

## SYNOPSIS

```
void VistaIOError (format [, arg...])
VistaIOStringConst format;
```

**void VistaIOSystemError (***format* \[**,** *arg*...\]**)**

**VistaIOStringConst** *format***;**

## ARGUMENTS

- *format*

  **Specifies the format of the message that is to be reported.**

- *arg*

  **Specifies values that are to be included in the formatted message.**

## DESCRIPTION

**VistaIOError is called to report a fatal error. It composes an error** **message and passes it to the fatal error handler, which typically prints** **the message and terminates the program (see [VistaIOSetErrorHandler(3)](/VistaIOSetErrorHandler/3.md)).**

**The message composed by VistaIOError is of the form:**

```
Program: Fatal: Description.
```

*Program***, the program's name, is included if it has been previously**  **established with a call to VistaIOSetProgramName.** *Description* **is a** **string that has been formatted by sprintf using format, plus** **all of the optional arguments,** *arg***.**

**VistaIOSystemError is identical to VistaIOError except that it also** **includes in the message a phrase based on the current value of the external** **variable errno, which is used by system calls to return diagnostic** **codes. The message composed by VistaIOSystemError is of the form:**

```
Program: Fatal: Description: Diagnostic.
```

*Diagnostic* **is a short phrase corresponding to the value of errno.** **This phrase is drawn from the table used by [perror(3)](/perror/3.md).**

## RETURN VALUES

**Neither VistaIOError nor VistaIOSystemError ever return.**

## EXAMPLES

**In this first example, the values of attr\_name, act\_value,** **and exp\_value are incorporated into the error message produced by** **VistaIOError.**

```
char *attr_name;
float act_value, exp_value;
if (act_value != exp_value)
	VistaIOError ("MyRoutine: Attribute %s is %f rather than %f",
		attr_name, act_value, exp_value);
```

**In this second example, the diagnostic phrase corresponding** **to the value of errno is incorporated into the error message produced by** **VistaIOSystemError.**

```
if (ioctl (fd, request, arg) == -1)
	VistaIOSystemError ("MyRoutine: ioctl failed");
```

## SEE ALSO

[**VistaIOWarning**(3)](/VistaIOWarning/3.md), [**VistaIOSetErrorHandler**(3)](/VistaIOSetErrorHandler/3.md), [**VistaIOSetProgramName**(3)](/VistaIOSetProgramName/3.md), **,** [**perror**(3)](/perror/3.md)

## AUTHOR

**Art Pope \<pope@cs.ubc.ca\>**

**Adaption to vistaio: Gert Wollny \<gw.fossdev@gmail.com\>**